tmk_core/ring_buffer.h

   1 #ifndef RING_BUFFER_H
   2 #define RING_BUFFER_H
   3 /*--------------------------------------------------------------------
   4  * Ring buffer to store scan codes from keyboard
   5  *------------------------------------------------------------------*/
   6 #define RBUF_SIZE 32
   7 static uint8_t rbuf[RBUF_SIZE];
   8 static uint8_t rbuf_head = 0;
   9 static uint8_t rbuf_tail = 0;
  10 static inline void rbuf_enqueue(uint8_t data)
  11 {
  12     uint8_t sreg = SREG;
  13     cli();
  14     uint8_t next = (rbuf_head + 1) % RBUF_SIZE;
  15     if (next != rbuf_tail) {
  16         rbuf[rbuf_head] = data;
  17         rbuf_head = next;
  18     } else {
  19         print("rbuf: full\n");
  20     }
  21     SREG = sreg;
  22 }
  23 static inline uint8_t rbuf_dequeue(void)
  24 {
  25     uint8_t val = 0;
  26
  27     uint8_t sreg = SREG;
  28     cli();
  29     if (rbuf_head != rbuf_tail) {
  30         val = rbuf[rbuf_tail];
  31         rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE;
  32     }
  33     SREG = sreg;
  34
  35     return val;
  36 }
  37 static inline bool rbuf_has_data(void)
  38 {
  39     uint8_t sreg = SREG;
  40     cli();
  41     bool has_data = (rbuf_head != rbuf_tail);
  42     SREG = sreg;
  43     return has_data;
  44 }
  45 static inline void rbuf_clear(void)
  46 {
  47     uint8_t sreg = SREG;
  48     cli();
  49     rbuf_head = rbuf_tail = 0;
  50     SREG = sreg;
  51 }
  52
  53 #endif  /* RING_BUFFER_H */